CVE-2022-48521Public exploitNetwork attack vector

Sender spoofing via shifted header deletion indexes

Published Jul 11, 2023 · Updated Aug 3, 2024

Improper header removal in OpenDKIM 2.10.3 and earlier and 2.11.x through 2.11.0-Beta2 allows remote attackers to spoof DKIM results. In mlfi_eom, forward iteration passes incrementing indexes to smfi_chgheader even though each deletion shifts the remaining Authentication-Results headers. The default KeepAuthResults=no setting exposes mail flows, and downstream programs that trust the surviving forged result can accept an unsigned sender as DKIM-authenticated.

CVSS severity5.3
Medium
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper header removal in OpenDKIM 2.10.3 and earlier and 2.11.x through 2.11.0-Beta2 allows remote attackers to spoof DKIM results. In mlfi_eom, forward iteration passes incrementing indexes to smfi_chgheader even though each deletion shifts the remaining Authentication-Results headers. The default KeepAuthResults=no setting exposes mail flows, and downstream programs that trust the surviving forged result can accept an unsigned sender as DKIM-authenticated.

The record

CVE
CVE-2022-48521
Published
Jul 11, 2023
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1565.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1565.002Transmitted Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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